Question

Charlie's weight is nine kilograms greater than his brother's. Together they weigh 99 kilograms. Let x represent the weight of the little brother. Which equation can be used to determine what each one weighs?

Answer 1

Charlie's weight is represented by the expression x+9. Since the equation needs their weights totaled, you must add x and x+9 and set it equal to 99 to get *2x + 9 = 99*

Answer 2

If the weight of the little brother is x, then the weight of Charles is x + 9

The equation that can be used to determine what each one weighs is:

x + (x + 9) = 99.

Let us now solve it.

x + x +9 = 99

2x + 9 = 99

2x = 99 - 9

2x = 90

x = 90/2

x = 45

Little brother's weight is 45 kg.

Charles' weight will be 45 + 9 = 54 kg

Adding these two weights will give 99kg